If "Oops!", see if your ISP redirects your DNS lookups to their DNS service:(Trailing dot is part of the command!)nslookup -type=txt which.opendns.com.nslookup -type=txt which.opendns.com. 208.67.222.222

Btw, you have selected "Dynamic IP (DHCP)" as internet connection type. This is rather unusual. You may want to try with PPPoE and "Dynamic IP", but you would need a username and password for this kind of internet access from your ISP. If you have, try it out!

"i disabled DNS relay in the router and then my laptop could not communicate with a DNS server "

Then you have no external DNS server IPs on the computer, but just the LAN IP of the router. [[DNS Servers : 192.168.0.1]] This is normal. (Although I swear I had run into a router a couple years back where this was reversed.)

I would see about rotblitz's suggestion regarding the WAN connection type. Also, comcast may serve your DNS queries regardless, but maybe there is a way to opt out. Some Comcast customers do have their DNS redirected - and apparently if you use the Constant Guard software from Comcast, you DNS will also be redirected. See here:https://forums.opendns.com/comments.php?DiscussionID=12561#Item_38 and below.

"i need the router to force openDNS for the whole network "

The DNS on local machines takes precedence over the router unless you set router firewall rules.

Did you consult D-Link support features? I would think this is the point to do so, because this seems to be a router problem, static DNS server addresses not taking effect. So not much to do with OpenDNS.

Only if you can set DNS only to static will this work. Otherwise you end up with no connection to the ISP.

I would suggest, at this point, that you unplug the router for a few minutes until the capacitors full discharge, plug it back in, and see what happens. Failing that, I would try resetting the router, then re-configuring the OpenDNS addresses. If that fails as well, you should check with D-Link support. In my limited experience, the 615 was always a good, solid, configurable router which worked well for many people.